Fifteen Filipino sailors of a Greek-owned tanker were rescued by Nigerian naval forces a day after their ship was hijacked by pirates last month, the Department of Foreign Affairs said Friday.

The local manning agency of the Filipino crew reported to the DFA that the vessel MT Norte was seized by armed men on the evening of Aug. 16. Nigerian forces launched the rescue operation on Aug. 17.

Foreign Affairs spokesman Raul Hernandez said the Filipinos were all “unharmed and safe” and were brought to the Nigerian Naval Base in Warri state for debriefing after the successful rescue operation.

They returned to their vessel on Thursday and are currently en route to the Nigerian city of Lagos, Hernandez said.